The present invention relates to a tube for the fluid fuel transport, particularly of a gasoline, to engines, in particular motor cars and to the method of making the same. The tube which is the subject of the invention is a polyamide tube lined internally with a polyvinylidene fluoride film.
For reasons of safety and of environmental protection, the automotive manufactures lay down for gasoline supply tubes mechanical characteristics--resistance and flexibility--and characteristics of increased resistance to permeability. The tubes must be as impermeable as possible to oil products and to their additives, in particular to methanol.
At the present time, polyamide tubes are usually used in the automotive industry. Polyamides represent an ideal material for this tube application, their mechanical resistance being excellent and their flexibility being sufficient so that a tube withstands, without breaking, during practically the entire life of the vehicle, the accumulation of flexions. These polyamide tubes no longer satisfy the new requirements of automotive manufacturers relating to permeability. With the increasing usage of methanol in gasoline, the sensitivity of the polyamide tubes manifests itself in a swelling of the tube leading to a decrease in the mechanical properties and to dimensional modifications.